Thoughts? tree launcher shoots line up to 250 feets

I have zero problems with new members trying to sell something: I just want them to be honest and aboveboard with all of it.
 
I was hoping for an explanation as to how his apparatus was "more accurate" than the APTA, but I guess he was too busy to type out the essay in reply.....
 
https://youtu.be/SAIH7HYbdSI. Here is a variation on the big shot I made a couple of years ago. Wanted something short that I could shoot like a gun. Skateboard wheels for pullies, archery trigger. Worked okay up to about 75 feet. Regular big shot is better. I still just hand throw. Fun project though.
 
I liked this fellow's modifications to the APTA -- he calls it the "APTA Old Fart Edition" (reticle sight, longer pressure chamber, mortar position):
<iframe width="560" height="315" src="https://www.youtube.com/embed/bOViCBNOkVA" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

and with a Butterfly valve instead of a ball valve:
<iframe width="560" height="315" src="https://www.youtube.com/embed/cOOWkN5h1PI" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
A ball valve will be cheaper in that size, and hold more reliably, and release the same. In his defence tho, I've fought with engineers over the same question more times than i can count.
 
Having the butterfly valve is a huge improved over the ball valve. Not because it is stronger but because it dumps the air chamber faster and with less physical movement. I also agree with OF that launching from a shoulder position is the least consistent. Not a fan of CO2 (as it will change with temperature) for the load force or the use of a red dot sight that limits you to positioning yourself to sight down it. With a 12oz bag and 1.75" zing-it the APTA should reach close to one vertical foot per pound of chamber pressure.
 
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You are correct in very low handle angles, but it soon takes over the butterfly valve. I didn't realise that a plug valve (usually used for natural gas and is easier to come by than a butterfly) is better than both both and is still a quarter turn valve. Anyways you can also reduce up to a larger valve to help with flow. Anyways, they are all really similar, and maybe a spring loaded valve actuator (ie a bungee cord with a trigger mechanism) would be an actual improvement? I dunno, i need to build one, but i already have a big shot....
 
If you look closely at that chart, (assuming I'm reading it right) it shows that the butterfly valve dumps a lot more than the others when it is just beginning to open.
Being that it is holding high pressure air, that makes a big difference and gets things going with authority.

I really, really want to play around with a coil spring under the valve arm. A trigger would make it way better and its damn good as it is.
 
You guys are funny with your charts and plans.
Reality is the throw line and how it pays out. Everything else is secondary.

I wager a west coast daily climber rate (300-500) that all your charts and stuff are crap in actually setting a line in the world of the redwoods or giant sequoias.
Put your chart to the test! :)
 
Whatever happened to oldfart. He was a fixture on tje buzz for a while. Havent heard from him in a while. New hobby maybe.
 
Frans, that sounds like an invite, and i would love to see the redwoods, let alone climb them! Although at this moment in my life, that graph would be especially boring, because i can't possibly swing that for quite awhile :cry:

You are right about the chart, but they are all very similar in performance was my attempted point. I have made this explicitly clear before, i do trees part time as best, but I'm a union steamfitter and pipeliner as a day job, so piping is something i can actually contribute on. And if i built one, just on that challenge alone i would have to do a welded one, that i could pressurise to a couple thousand psi, so :P
 
We'll get back to you, when we need to set a throwline to the moon, Kyle.
 
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